This organopolysiloxane composition for use in release paper or release film, said organopolysiloxane composition containing (A) an organopolysiloxane having two or more silicon atom-bonded alkenyl groups in each molecule, (B) an organohydrogen polysiloxane having two or more silicon atom-bonded hydrogen atoms (Si—H groups) on average in each molecule, (C) an organic peroxide and (D) a specific amount of a platinum group metal-based catalyst, is capable of undergoing an addition reaction with a smaller amount of the platinum group metal-based catalyst in comparison to the prior art, thereby being capable of forming a cured coating film which has a release strength equivalent to that of the prior art even in cases where a component that inhibits the catalytic activity of the platinum group metal-based catalyst is contained in the composition. In addition, this organopolysiloxane composition is capable of forming a cured coating film by means of an addition reaction even on a base material containing a catalyst poison component, on said base material conventional compositions being not able to be cured.

The present invention is a thermally conductive sheet comprising a plurality of unit layers, each comprising a silicone resin and a thermally conductive filler, the plurality of unit layers being laminated such that the plurality of unit layers are adhered to each other, wherein a volume content of the silicone resin is 32% by volume or less, and a compressive load at a sheet area of 25.4 mm×25.4 mm when the thermally conductive sheet is 30% compressed from a direction perpendicular to an adhesion plane on which the plurality of unit layers are adhered to each other is 7.0 kgf or less. According to the present invention, it is possible to improve the thermal conductivity and enhance the softness of a thermally conductive sheet using a silicone resin as a matrix component and composed of a large number of unit layers laminated as compared with the conventional one.

The present invention is a thermal conductive silicone composition comprises (C) one or more aluminum nitride particles selected from an irregular-shaped, a round, and a polyhedral particles having an average particle size of 4 .Math.m or more and less than 50 .Math.m; (D) one or more aluminum nitride particles selected from an irregular-shaped, a round, and a polyhedral particles having an average particle size of 50 .Math.m or more and 150 .Math.m or less; and (E) an inorganic particle having an average particle size of 0.1 .Math.m or more and less than 4.0 .Math.m. This provides a thermal conductive silicone composition ensuring both high thermal conductivity and shift resistance.

A crosslinked silicone material Y obtained by heating to a temperature of between 70 and 200° C., a crosslinkable composition X including an organopolysiloxane compound A containing, per molecule, at least two C.sub.2-C.sub.6 alkenyl radicals bonded to silicon atoms; an organohydrogenopolysiloxane compound B containing, per molecule, at least two hydrogen atoms bonded to an identical or different silicon atom; a catalyst C of formula [Ni(L.sup.1).sub.2] where Ni represents nickel at degree of oxidation II; L.sup.1 which may be identical or different, represents a β-dicarbonylato anion or the enolate anion of a β-dicarbonylated compound; optionally an adhesion promoter D; and optionally a charge E.

Provided are rapidly cross-linkable silicone foam compositions, kits, and methods for filling implanted medical devices in situ or in vivo, the implanted medical devices, including for example, body implants and tissue expanders, the compositions including a platinum divinyl disiloxane complex; a low viscosity vinyl terminated polydimethylsiloxane; a low viscosity hydride terminated polydimethylsiloxane; a silicone cross-linker; and a gas and/or gas-filled microcapsules, where the rapidly cross-linkable silicone foam composition has a viscosity of ≤150 cPs for ≥1 min. post-preparation and ≤300 cPs≤5 min. post-preparation, at ambient temperature.

A process to form a crosslinked composition, the process comprising thermally treating a composition that comprises the following components: a) at least one olefin/silane interpolymer comprising at least one Si—H group, b) at least one peroxide, and c) optionally, at least one crosslinking coagent. A composition that comprises the following components: a) at least one olefin/silane interpolymer comprising at least one Si—H group, b) at least one peroxide, and c) optionally, at least one crosslinking coagent.

A composition for forming a foamed silicone elastomer is disclosed. The composition comprises: A) an organopolysiloxane having at least two silicon-bonded ethylenically unsaturated groups per molecule; B) an organohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; C) a hydrosilylation catalyst; D) a chemical blowing agent; and E) a physical blowing agent. The hydrosilylation catalyst C) is present in a catalytically effective amount. The chemical blowing agent D) has at least one hydroxyl (OH) group, and is present in an amount to provide a OH content >0 and <500 parts per million (ppm). The physical blowing agent E) undergoes a phase change from a liquid to a gaseous state during exposure to atmospheric pressure and a temperature ≥0° C. The blowing agents D) and E) are different from one another. A foamed silicone elastomer, and methods of forming the composition and foamed silicone elastomer are also disclosed.

A process for the modification of a surface of a solid material having the step of contacting the surface with a surface-modifying composition under irradiation with light of a wavelength in the range of 200 to 800 nm, optionally in the presence of a photoinitiator, wherein the solid material is chosen from the group consisting of polyesters, polyethers, polycarbonates, polyketones polyamides, polyurethanes, (meth)acrylate and (meth)acrylamide polymers and polyetherimides and wherein the surface modifying composition includes at least a hydrosilane.

Disclosed is a preparation method for a polysiloxane powder filler. The method comprises: providing polysiloxane which contains at least 60 wt % of T unit, wherein T unit is equal to R.sub.1SiO.sub.3-, R.sub.1 is a hydrogen atom or an independently selected organic group comprising 1-18 carbon atoms; and performing heat treatment on the polysiloxane under inert gas atmosphere or vacuum conditions, wherein the heat treatment temperature is 250 to 750 degrees, such that silicon hydroxyl groups in the polysiloxane are condensed to obtain a polysiloxane powder filler having a true density greater than or equal to 1.33 g/cm.sup.3 and more preferably greater than or equal to 1.34 g/cm.sup.3. The polysiloxane powder filler obtained by the described preparation method has low inductivity, low inductivity loss and low radioactivity; and can be used for semiconductor packaging materials, circuit boards and intermediate semi-finished products thereof, and semi-cured sheets or copper clad laminates of high-frequency high-speed circuit boards.

Novel methods for producing porous silicone compositions are disclosed. Methods of this invention provide improved processes for preparing porous silicone rubbers having low specific gravity and mainly closed cells which are suitable for highly permeable gas penetration while adequately sealing liquid material. Examples of these sealing materials include but are not limited to encapsulants for bioindicators and syringe sealing components wherein the permeability is sufficient to permit sterilization while preventing passage or leaking of liquids to be sterilized through the described silicone materials.